The subject matter disclosed herein relates to process control systems and device diagnostics, with particular discussion about a method and system architecture to provide data to a user interface to support trend analysis and display in real-time.
Process lines may include many varieties of flow controls. These process lines typically transfer fluids for use in the chemical industry, refining industry, oil & gas recovery industry, and the like. Examples of the flow controls include pneumatic and electronic valve assemblies (collectively, “valve assemblies”) that regulate a flow of process fluid (e.g., gas and liquid). In conventional implementation, these valve assemblies have a number of components that work together to regulate flow of process fluid into and/or out of the process line. The components include a closure member, a seat, a valve stem, and an actuator. Examples of the closure member may embody a plug, ball, butterfly valve, and/or like implement that can contact the seat to prevent flow. In common constructions, the actuator couples with the closure member (via the valve stem). The valve assembly may also incorporate a valve positioner with electrical and/or electro-pneumatic components. During operation, the valve positioner receives control signals from a controller that is part of a process control system (also “distributed control system” or “DCS system”). These control signals define operating parameters for the valve assembly, namely, a position for the closure member relative to the seat. In response to the control signal, the valve positioner delivers a pneumatic signal that regulates instrument gas to pressurize the actuator in order to regulate this position.
Problems with valve assemblies on the process line may disrupt the process and/or prevent the process line from achieving the necessary process parameters. The resulting disruptions can lower yields and reduce quality. In large refineries, chemical plants, and power plants, disruptions can also lead to significant expense from process downtime that is necessary to troubleshoot and repair the problematic devices. Plant operators therefore have an interest to perform diagnostics on the valve assemblies to detect problems at the device-level, for example, before problems manifest in ways that can hinder sustainable operation of the process line. These diagnostics can leverage tools that present information to the plant operators. These tools include software packages that process and display the data, typically to a user interface that displays on a computer or a workstation. In this manner, an end user can observe the user interface to evaluate operation of the process devices.
Notably, advances in technology that relate to data transmission, data storage, and data processing allow plant owners and operators to monitor performance of devices at a very granular level. By implementing appropriate analysis, plant owners and operators can often predict with great accuracy the potential for failure in a singular device before problems can occur and disrupt operation of a plant or a process line. Such foresight is critical for the plant operator to make judgments about maintenance and repair schedules, to reduce labor costs, and to maintain efficient operation of the plant or process line.
Conventional tools that allow the plant operator to perform device diagnostics have not kept pace with expanding amounts of data that is available for analysis. Many conventional tools have interfaces that complicate access to the wealth of information that is available to the individuals that are responsible for oversight of the facility. These interfaces may require multiple interactions (or “clicks”) from the end user simply to drill down into the data at the device-level. Moreover, the tools often rely on antiquated approaches that tether access by the end user to a single point or location, e.g., a desktop computer.
For process and control industries, these approaches do not exploit other modalities the end user might use to view and interact with the information. But failure to leverage wired and wireless technologies and related devices (e.g., smart phones, tablets, etc.) forego much efficiency that would help the plant operator operate the plant more efficiently. Exemplary technologies include server-client systems that enable web-based interfaces using a web browser (and related technology) and a server that can process data at the valve assembly-level and deliver the data to the web-based browser.
Migration of display requirements to web-based user interfaces has exposed some limitations in conventional tools. However, system architecture at the server can frustrate delivery of data to the web browser in a manner sufficient to enable the user interface to best situate the end user to diagnose problems of a specific or individual valve assembly on the process line. It has been found, for example, that varying data sampling rates, data exchange/communication rates, and data processing rates are rarely matched and synchronized as necessary to appropriately retrieve and process data from the valve assemblies and to smoothly display the data on the web-based user interface. The deficiencies often render the tools unable to convey “live” or real-time data to a browser; instead providing static displays with limited functionality.